Expansive fluid-actuated pilot-controlled valve mechanism for motors of reciprocating pumps



Dec. 19, 1939. BUTLER 2,183,538

EXPANSIVE FLUID-ACTUATED PILOT-CONTROLLED VALVE MECHANISM FOR MOTORS 0FRECIPROCATING PUMPS Filed Jan. 21, 1938 3 Sheets-Sheet 1 Dec. 19, 1939.F. D. BUTLER 2,183,538

EXPANSIVE FLUID-ACTUATED PILOT-CONTROLLED VALVE MECHANISM FOR MOTORS 0FRECIPROCATING PUMPS Dec. 19, 1939. F. D BUTLER 2,183,538

EXPANSIVE FLUID-ACTUATED PILOT-CONTROLLED VALVE MECHANISM FOR MOTORS 0FRHCIPROCATING PUMPS Filed Jan. 21, 1938 3 Sheets-Sheet 3 FMEMM PatentedDec. 19, 1939 UNITED STATES PATENT. OFFICE,

EXPANSIVE rwm-Acrmran ruler-conraotnan VALVE MECHANISM roa mocross oranorraocarmarunms Frank 1mm Bum}, United sum it." Application January21,1838, Serial No. 1m-

8 Claims. (or. 121-151) (Granted under the not of March 3, 1883, as

amended Apl'll 8., 1928; 370 0.

My present invention relates to valve operating mechanisms for motors ofreciprocating pumps wherein the pflot valve or valves of such a motor ismechanically operated either directly or in- 6 directly by the mainpiston and wherein the main valve of such motor is actuated by expansivefluid which latter is controlled by such pilot valve or valves.

The major concept of my present invention is 10 the provision of asimple, compact, efllcient, durable and relatively inexpensive valveassembly for the type of motor mentioned.

More specific concepts of my invention contemplate the followingfeatures:

The provision of a spool shaped mainvalve member which is adapted tobe'slidably mounted within a cylindrical bore of a suitable valve chestlocated adjoining the cylinder of the motor, the main valve member tohave a plurality of cylindrical shaped fluid actuating chambers for thepurpose of alternately containing the expansive fluid for actuating themain valve, one being located adjoining each end thereof and both havinga plurality of diameters with a seat interposed between the plurality ofdiameters;

The provision of a pair of valve chest bore covers, one for each end ofthe valve chest bore, both having suitable shoulder projectionsextending' inward in said valve chest bore and adapted to support saidmain valve centrally within said bore;

The projection of each of such covers having a plurality of diameterswith a suitable shoulder seat portion interposed between such pluralityof 85 diameters and corresponding to the plurality of diameters andinterposed seats therebetween of the fluid actuating chambers of saidmain valve;

The provision of a pair of elongated cylindrical shap d pilot valvemembers slidably mounted parallel to the bore of the main motorcylinder, one located adjoining each end of said cylinder, both beingadapted to be actuated by the main piston of the main motor cylinder andeach being adapted to control the expansive fluid supply to and exhaustfrom the main valve fluid actuating chamber adjoining its respective endof such cylinder;

And the provision of means comprising new and useful entities whichpractically, commercially, efliciently and economically practice to bemost advantageous in each of the foregoing, and such other respectswhich will more clearly appear and be understood by those skilled inthis art, from the accompanying drawings and the following description,and the appended claims.

It will be readily appreciated by those skilled in this art. afterunderstanding my invention, that various changes be made in themeansdisclosed herein which will produce thesame results in substantially thesame manner without di- 5 gressing substantially from my inventiveconcept or sacrificing any of its outstanding inherent advantages.

With reference to the drawings:

Fig. 1 is a vertical section through the embodi-v l0 ment of my pilotcontrolled, fluid actuated valve mechanism as applied to 'the cylinderof a pump motor;

Fig. 2 is a view in plan as takenlon the dotted line 2-2 of Fig. 1, thelower half being in plan, 16 the upper left quarter being on a plane ata level, with the, upper exhaust communication port, and the upper rightquarter being on a plane parallel to theupper cylinder communicationport;-

Fig. 3 is a fragmentary view of the various ele- 20 ments illustrated inFig.1, except illustrating the main valve at mid travel position and themain piston near its uppermost end of travel and diagrammaticallyillustrating the main piston near its bottom end of travel and with thepilot 25 valves in the position they wouldthen occupy;

Fig. 4 is similar to Fig. 3 except illustrating the main valve at fullupward travel and the main piston at the top end of its upward strokeabout to recede downward in the cylinder, and 30 also diagrammaticallyillustrating the piston near the downward end of its travel in aposition of gravel about to actuate the lower pilot valve mem- Fig. 5 isan enlarged fragmentary view of a 35 portion of the elements illustratedin Fig. 1, except that it illustrates the main piston near the downwardend of its stroke or travel with the main valve and lower pilot valve atabout onehalf of their downward travel; and, 40

Fig. 6 is a side elevation of my valve assembly installed in a pumpassembly.

In the drawings, in which the same reference characters indicate thesame parts in the several views, Fig. 6 illustrates the pump and motoras- 45 sembly with the motor cylinder I closely coupled to the pumpcylinder 2 by an intermediate thimble member 3. The motor piston 4 isconnected with the pump piston 5 by the main piston rod 6 and theexpansive fluid actuating medium 5 is supplied to and exhausted f1 amthe main motor cylinder I via the valve chez t-I secured to' thecylinder I by the stud bolts 8. v

The pump motor proper is as follows: A main cylinder body I has aninternal liner or bushing 5 insert la in which is a cylindrical mainbore lb closed at both ends by the upper and lower main cylinder heads 9and 9a respectively. Installed in the bore lb is a slidable andreciprocable main piston 4 with a suitable snap type piston ring 4a.This main piston 4 is coupled to the pump piston 5 by the common pistonrod 6 with a packing stufllng box in located in the lower cylinder headin. The main piston 4 is double acting in the main bore Ib due to theintermittent and alternate admittance and exhaust of the expansive fluidmedium to the main bore above and below the piston 4 through the upperand lower cylinder communication ports l and Illa respectively. Theseports III and I04 provide constant communication between the main borelb and the bore Ia of the valve chest I, and are provided with the mainpiston cushioning ports I. and I06 respectively, which in turn maintainconstant communication between said ports l0 and Illa and theirrespective ends of said main bore lb when the main piston 4 is at ornear the ends of its reciprocating travel in such bore.

The valve chest bore In. lies in a plane parallel to and closelyadjoining the main cylinder bore lb and has suitable upper and lowerliners or bushing inserts lb and 1c respectively. Installed in theliners Ib and I0 is a suitable elongated spool shaped slidable andreciprocable main valve II. This main'valve ll controls the expansivefluid supply to and exhaust from said main bore lb via the upper andlower cylinder communication ports II and Illa respectively by openingintermittently and alternately to the expansive fluid supply and exhaustports Id and le. The ports Id and le are located in the periphery of theupper and lower valve chest bore bushing inserts 1b and I0 respectivelyand coincide with ports l0 and Id.

The expansive fluid is supplied tothe bore Ia of the valve chest I fromthe source of supply. via the expansive fluid supply connection Iisecured to the external midsection of the valve chest and thence intothe expansive fluid supply chest lia cored out in the central portion ofthe valve chest and is in constant communication with the centralportion of the valve chest bore la.

The exhaust expansive fluid is expended from the valve chest bore Ia toits final destiny via the exhaust communication passageway lia which iscored in the body of the valve chest I and connects both ends of saidbore Ia with the exhaust outlet connection It, which latter is securedto the mid-section of said valve chest body opposite the expansive fluidinlet connection ii.

The main valve II is provided with snap type upper and lower rings Ilaand II b respectively mounted in suitable grooves located in theenlarged spool head portions thereof. These rings are machined widerthan the ports Id and le in the valve chest bore liners Ib and I0 andare adapted to intermittently and simultaneously pass from one side ofthe ports to the other during the movement offlae valve. The outer endsof the valve chest bore Ill-are closed by suitable.

upper and lower covers 'I! and lg respectively.

These covers I! and lg are provided with suitable projections Ih and Itrespectively which each extend inwardly into and centrally of the valvechest bore Ia and have a slidable fit with a plurality of cylindricalrecess bores located in the outer ends of the main valve l I. The upperproiection in has a plurality of diameters I7 and 'Ik with acylindro-conical portion Im interposed therebetween which all fit andcorrespond to a plurality oi diameters He and lid respectively with aconical seat portion lle interposed therebetween which latter three arelocated in the upper end of the main valve II. The lower projection Iihas a similar plurality of diameters 17" and lit with a cylindro-conicalportion 'Im' interposed therebetween which similarly all lit andcorrespond to a plurality of diameters lie and lid respectively, with aconical seat portion lle' interposed therebetween which latter three arelocated in the lower end of the main valve I l.

Suitable upper and lower actuating motor cylinders II and I ifrespectively for the main valve II are provided intermediate the inwardends of the projections lb and Ii and the inward ends of said recessbores in the ends of said main valve. Suitable upper and lower exhaustcushioning dash pots Hg and Hg respectively for the main valve II areprovided intermediate the cylindro-conical portions Im and Im' and thelarger diameters lit and lit respectively or the projections U1. and Ii.

Suitable elongated, cylindrical, shouldered upper and lower pilot valvesl4 and Ma for the main valve l I are slidably mounted in suitablebushing inserts l4 and Ma respectively which are pressed into the upperand lower cylinder heads 9 and 9a respectively and which lie in a planeparallel to the main cylinder bore lb. -The inward ends of these pilotvalves are smaller than the outer ends thereof and are adaptedto projectinto the bore lb and to each alternately be contacted by the piston 4 asthe piston 4 nears the end of its stroke in the bore. The outward endsof these pilot valves have integral therewith the enlarged head portionsNb and MD with frusto conical shoulders which are adapted to closeagainst corresponding seats 0 and He located in the outer ends of theirrespective bore liner inserts l4 and Ma. Outward oi. the inserts I4 andI 4a in the cylinder heads 9 and 9a respectively are mounted theexternally threaded hollow plugs Nd and l4d' which form suitablepressure chambers lib and lib outward from the seats I40 and Herespectively. Port communication is established between the expansivefluid supply chest lia in the central portion'of the valve chest and thepressure chambers lib and lib and the expansive fluid may flow from thechest lia through the ports lie and lie in the chest I, thence throughthe ports lid and lid in the upper and lower chest covers If and lgrespectively, thence through the ports lie and lie in the upper andlower cylinder heads I and 9a, and thence through the ports iii and Iiiin the inserts l4 and Ma and into the pressure chambers lib and librespectively. Inasmuch as the pressure of this supply expansive fluid isalways a trifle higher than the maximum pressure within the maincylinder bore lb, the pilot valves l4 and Ma are retained by this higherpressure in their full inward or normal position of travel, in whichthey are illustrated in Fig. 1, except when con-- tacted as illustratedin Fig. and upper portion of Fig. 4 by the main piston 4. Portcommunication is likewise established between the bore of the linerinserts l4 and'l4a' and the main valve actuating chambers Ill and II!respectively and between said bore of the inserts and the supplyexpansive fluid pressure chambers lib and lib respectively.

The expansive fluid may flow when pilot valves l4 and Ma are in theirnormal positions, as illustrated in Fig. 1, from said pressure chamberslib and lib through the grooves lip and lig' which latter are cutthrough the seats I40 and He at a point coincident with the inward endsoi ports I2! and I2! respectively, thence through the annular shapedchambers I2h and I 2h which are always in constant communication withchambers I Iband I2b' respectively whichare formed between the innerbores of the inserts ll and Ila and reduced portions of the pilot valvesII and Ila at a point adjoining the inward ends of the pilot valve headsIlb and Nb of the latter respectively, thence through the radial portsI22 and I21 in the inserts Il' and'I la respectively. thence through theports I'M and Ili'located in the upper and lower main cylinder heads 9and 90 respectively, and thence through the ports I2Ic and I2lc' locatedin the valve chest covers If and lg and extending through theprojections in and Ii of the latter and into the upper and lower mainvalve actuating chambers IIj and III respectively. This supplycommunication between the pressure chambers I2b and lib and the mainvalve upper and lower actuating chambers I I f and II respectively isout off or terminated and exhaust communication established between theactuating chambers II f and II I and the exhaust passageway I 3a whenthe pilot valves Il and Ila are actuated by being contacted by the mainpiston l and moved outward beyond about one-third of their full outwardtravel similar to any one of the-positions in which they are illustratedin Fig. 5 and upper portions of Figs. 3 and 4.

When the pilot valves are in these positions of outward travel, theexpended expansive fluid may flow from the actuating chambers Hi andII)" through the actuating chamber communication ports I2k and I270,thence through the continuation communication ports I 21 and I21, thencethrough a further continuation of the communication ports terminating inthe radial ports I22 and I2i" all respectively, thence through theannular shaped exhaust chambers I31) and I3b. These chambers I3b andI3b' are always in constant communication with the exhaust passagewayI3a. These chambers are formed between the inner bores of the inserts lland Ila and reduced portions of the pilot valves I4 and Ilarespectively. These reduced portions are located at a point on thevalves intermediate their center non-reduced portions I le and I le andtheir inward end non-reduced portions Ilf and I4)" respectively. Thefluid thence flows through the exhaust ports I30 and I30 extendingradially through the inserts M and Ila. The flu d continues from thechambers I3b and I3b through openings I30 and I30 through the exhaustports I3d and I3d' located in the main cylinder heads 9 and. 9a, thencethrough the exhaust ports I3e and I3e' located in the valve chest coversIf and 19' all respectively, and into the exhaust communicationpassageway I 3a.

Suitable flange joint connections are made between the inward flangefaces of the upper and lower valve chest covers If and lg and the upperand lower end f as respectively of the valve chest I, and als betweenthe side faces of the upper and lower valve chest covers If and la andthe side faces of the upper and lower main cylinder heads 9 and 9arespectively. These covers are secured to the valve .chestby thestud-bolts 8a, and are secured to the cylinder heads by the stud-bolts8b, thus establishing enclosed or pipeless port communication systemsextending through the covers and heads for the supply and exhaust of theactuating expansive fluid to and from the main valve actuating chambersII] and II)" via the control pilot valves I4 and Ila respectively. Theyalso provide for passage of the supply expansive fluid from the supplychest I2a to the pressure chambers I2b and I2b' adjoining the outer endsof the control pilot valves Il and Ila respectively.

Starting with the moving elements of the motor in the position inwhichthey are illustrated in Fig. 1, the operation of the motor is asfollows: The space beneath the main piston 4 within the main bore Ib isin open communication with the expansive fluid supply chest I2a, and thesupply expansive fluid flows from the chest I2a through the radial ports'Ie, into the. lower cylinder communication port Ina, and thence intothe space in said main bore beneath said main piston l. Simultaneowlywith the expansive fluid supply entering the space beneath the piston,the space above the piston within the main bore Ib is in opencommunication with the expansive fluid exhaust communication passagewayI3a and the expended expansive fluid above the main piston is free toflow therefrom through the upper cylinder communication port II) and theports Id into the exhaust communication passageway I3a. The main valvecontrol pilot valves Il and Ila in the meantime are retained in theirinward,

normal positions of travel in which they are in contact with the seatsIlc and Mo respectively by the higher pressure of the expansive fluid inchambers I 2b and I2b' over that in the main cylinder bore lb.

Th s admittance of supply expansive fluid beneath the main piston andsimultaneous exhaust of the expended expansive fluid above the mainpiston causes the piston to travel upward from the position in which itis illustrated in Fig. 1 to the positon in which it is illustrated infull lines in Fig. 3, and thence on to the position in which it isillustrated in full lines in Fig. 4. As the main piston l is thus forcedupward in the bore Ib from the Fig; 1 to its position Fig. 4, the upperside of the piston contacts the inward end of the upper pilot valve I4and forces the pilot valve upward from the position in which it isillustrated in Fig. l to the position in which it is illustrated in fulllines in Fig. 3, and thence on to the position in which it'isillustrated in full lines in Fig. 4. This upward movement of the upperpilot valve I 4 causes the non-reduced center portion Ile thereof tofirst pass over and to thus close oif port I2i, thus closing of! supplycommunication between chamber I21) and the main valve upper actuatingchamber'llf, and then continue on upward beyond the port I21 to thusopen exhaust communication between the actuating chamber III and theupper end of the exhaust communication passageway I3a and therebyrelease the expended expansive fluid in the actuating chamber and allowit to flow therefrom to the passageway I3a. Ths releasing of theexpansive fluid from the actuating chamber Hi to the exhaust makes itpossible for the live or supply actuating fluid in the main 'valve loweractuating chamber II)" at this time formed inward of the small diameter17" in the small bore II c to overpower the lower pressure in said upperactuating chamber II f at this time formed inward of the relativelylarge diameter 1k in the similar size bore lid, and thus force the mainvalve II from the position in which it is illustrated in Fig. 1 to theposition in which it is illustrated in Fig. 3, thence to the position inand arrives at the position in which it is illustrated in Fig. 3, thelower snap ring I lb in the main valve covers the ports Ia and cuts offor terminates the supply of expansive fluid from the supply chamber lidto the space in the main bore lb beneath the main piston 4.Simultaneously the upper snap ring Na in the main valve covers the portsId and thus terminates the expended expansive fluid release or exhaustfrom the space in the main bore lb above the main piston to the exhaustcommunication passageway l3a. As the main valve II continues its upwardtravel from the position in which it is illustrated in Fig. 3 to theposition in which it is illustrated in Fig. 4, the lower snap ring IIbpasses upward beyond the ports 1e and opens communication between thespace in the main bore lb beneath the main piston 4 and the lower end ofthe exhaust communication passageway I3a to thereby release the expendedexpansive fluid beneath the main piston and allow it to flow freelytherefrom through the lower cylinder communication port Inc and theports 'Ie into the lower end of the exhaust passageway Ila.

Simultaneously with the foregoing release of the expended expansivefluid from beneath the main piston and during such continued upwardtravel of the main valve, the upper snap ring Ila passes upward beyondthe ports Id and opens communication between the expansive fluid supplychest Ila and the space in the main bore Ib above the main piston 4 toadmit live or supply expansive fluid from the chest Ila via the ports Idand Ill into the space above the main piston. Simultaneously during thiscontinued upward travel of the main valve II from the position in Fig. 3to the position in Fig. 4, and approximately simultaneously as theinward end of the small diameter Ii clears the outward end of the smallbore He, thus temporarilyincreasing the size of the lower actuatingchamber III, the small diameter I7 enters the outward end of the smallbore lie and thus temporarily decreases the size of the upper actuatingchamber II! and also forms an annular shaped cushioning dash-potexternal to said small diameter Ii and internal to the relatively largebore lid. The exhaust expansive fluid thus trapped in this annularshaped cushioning dash-pot is finally compressed into the relativelysmall annular shaped dash-pot compression space My as thecylindro-conical portion Im of the projection Hz is finally contacted bythe seat. I le of the main valve, thus cushioning the main valve as itnears the upward end of its travel, and eventually terminating theupward travel as the portion Im is contacted.

All communication ports and chambers through which the exhaust expansivefluid passes on being released from either of the actuating chambers IIIand II! are made of sufficient size so that the main piston 4 wouldordinarily be caused to short stroke due to the main valve II reversingthe actuating fluid supply and exupper and lower valve chest covers I!and la respectively in such a manner so that the size of the exhaustports lie and lie can be individually, externally and manually regulatedso as to adjust the stroke of the main piston during the period it is inoperation.

As the main piston 4 is forced downward due to the space above saidpiston being supplied with expansive fluid and the space beneath thepiston being open to the exhaust from the position in which it isillustrated in full lines in Fig. 4 to the position it is illustrated indotted lines in this figure, thence to the position it is illustrated inin Fig. 5, and finally to its full downward travel position asillustrated in dotted lines in Fig. 1, the upper main valve pilotcontrol valve I4 follows the piston downward in the early part of itstravel until it is again in its normal position in contact with itsshoulder seat I40. This closes of! the exhaust communication existingbetween the upper actuating chamber llf and the upper end of the exhaustpassageway I3a via the pilot valve I4, and reestablishes expansive fluidsupply communication between the supply chamber I2a and the upperactuating chamber I If via the pilot valve I4.

As the main pistoncontinues its downward stroke and nears the bottom endof its travel, it strikes or contacts the inward end of the lower pilotvalve Na and causes it to be forced outward from the position it isillustrated in in Fig. 4 to the position in which it is illustrated inFig. 5, and thence to the position it is illustrated in. the dottedlines Fig. 1, whereby the nonreduced central position Me of the pilotvalve I4a first passes over port iii and cuts off or terminates theexpansive fluid supply communication existing between the supply chestIla and the lower actuating chamber III via the pilot valve Ila. It thencontinues its travel outward beyond the port I21, uncovers this port andestablishes exhaust communication between the lower actuating chamberIII, and the lower end of the exhaust passageway l3a and allows theexhaust fluid from the actuating chamber to flow freely, unlessthrottled by the lower exhaust control valve I31, Fig. 6, therefrom intothe exhaust passageway l3a.

This release of the expansive fluid from. the relatively large loweractuating chamber II! to the exhaust makes it possible for the supplypressure of the expansive fluid in the temporarily small upper actuatingchamber III to over-power the lower pressure of the exhausting expansivefluid in the temporarily large lower actuating chamber Ilf and force themain valve I l downward from the position of travel in which it isillustrated in Fig. 4 to the position of travel it isillustrated in inFig. 5, and thence to position Fig. 1, during such downward travel ofthe main valve II. The upper snap ring Ila is thereby moved from aboveto directly over and thence below the upper port Id, which is inconstant communication with the space in the main bore lb above the mainpiston 4, and thus first cuts off or terminates the existing expansivefluid supply from the supply chest I2a to the bore Ib and then opens orestablishes exhaust communication between the port Id and the exhaustcommunication passageway I3a, thus releasing the expansive fluid abovethe piston 4 to the exhaust.

Simultaneously during this downward travel of the main valve II, thelower snap ring Ilb thereof is thereby moved from above to directly overlower port 'Ie, as illustrated in Fig. 5, and thence below the lowerport 'Ie which is in conmeans cuts oi! or terminates the existingexhaust of the expended expansive fluid from the bore lb to the exhaustcommunication passageway Ila and then opens or establishes communicationbetween the port la and the expansive fluid supply chest 12a, thusadmitting live expansive fluid beneath the main piston 4, thereby flrstcushioning it, and then causing it to reverse its downward motion andstart its upward stroke. This completes one complete double stroke cycleof operations. During this downward stroke of the main valve ii, thesmall diameter bore lie of the main valve passes downward over the smalldiameter ii and cuts oil! communication between dash-pot chamber llg'and port l2k in Ii, thus making it necessary for the main valve II tocompress the remaining exhaust expansive fluid in 9', Fig. 5, into thespace My, Fig. 1, and thus cushion thevalve before it contacts disc Theouter ends or heads of the pilot valves l4 and Ma are machined conicalso as to prevent these valves from forming a large contact with theinner sides of the hollow plugs Md and l4d' respectively, to form a sealtherebetween that would cause one or the other, especially the lower, ofthese valves to fail to return to its normal position of travel whereinit is in contact with its shoulder'seat. The main valve II is supportedsolely on the projections lb and Ii and does not touch the liner insertsof the valve chamber bore. The snap rings Ila and Nb of the main valveare the valve port control means and they alone contact the inner wallsof the inserts. These snap rings Ila and Ill) of the main valve II aremade sufliciently wide to slightly overlap the ports 1d and'leirespectively, as illustrated in part in Fig. .5, so as to produceboth a slight supply and exhaust lap. The main piston stroke controlneedle valves l3 and I3! are threaded into the upper and lower valvechest covers If and lg respectively and control the size of theactuating chambers II and III exhaust ports l3e and He respectively.These needle valves may be manually operated by the hand wheels I31 andare locked in position by the jam nuts l3h. The only moving element ofthis motor that is externally exposed is the piston rod.

Assuming that the main piston 4 and upper and lower pilot valves l4 andMa. respectively are in the position in which they are illustrated inFig. 1, and that the main valve II is in the position in which it isillustrated in Fig. 4, then the main valve ll would be sustained in theposition last mentioned against gravity and the pressure acting in thetemporary relatively small diameter'upper actuating motor cylinder illby the pressure acting in the temporary relatively-large diameter loweractuating motor cylinder llj' against the lower portion of valve ll.

' with reference to Figs. land 5, the exhaust cushion compression spaceMy, Fig. 1, should be of such volumetric capacity that the exhaustexpansive fluid trapped in the space llg, Fig. 5,

could not be compressed in the former mentioned space during the fulldownward travel of the main valve II to a pressure equal to that of theactuating-expansive fluid within chamber llf moving such valve lldownward.

It is obviously understood that this motor could be used on otherappliances than a pump assembly. 1

The invention described herein may be manufactured and/or used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

Having thus set forth and disclosed the nature of the invention, what isclaimed is:

1. In a motor for a pump having a cylinder containing a reciprocablepiston member actuated. within the cylinder by expansive fluid, a valvechest extending parallel to and secured to the cylinder, said chesthaving a cylindrically shaped bore, a main valve member slidably mountedin said bore of said valve chest to control the supply .and exhaust orthe expansive fluid to actuate the piston in the cylinder, said mainvalve memor said valve chest bore, and an inwardly extending projectionon each cover having a slidable flt to the two sizes of its mate recessin the end of said main valve member, said projections providing thesole supporting means for said main valve membercentrally within thebore of said valve chest.

2. In a motor for a pump having a cylinder containing a reciprocablepiston member actuated within the cylinder by expansive fluid, a valvechest extending parallel to and secured to the cylinder, said chesthaving a cylindrically shaped bore, a main valve member slidably mountedin said bore of said valve chest to control, the supply and exhaust ofthe expansive fluid to actuate the piston in the cylinder, said mainvalve member having a pair of cylindrically shaped recesses, one in eachouter end thereof, said recesses forming the actuating motor cylinderstherefor, each of said recesses having two diametrical sizes, afrusto-conical shoulder seat interposed between two diametrical sizes, apair of covers, one for each end of said valve chest bore, an inwardlyextending projection on each cover having a slidable fit to the twosizes of its mate recess in the end of said main valve member, saidprojections providing the sole supporting means for said main valvemember centrally within the bore oi said valve chest, and acylindro-conical shoulder intermediate the two sizesof each projection,each of said shoulders being adapted to contact with and form a sealwith its mate seat shoulder in its mate recess in said main valvechamber.

3. In a motor for a pump having a cylinder containing a reciprocablepiston member actuated within the cylinder by expansive fluid, a valvechest extending parallel to and secured to the cylinder, said chesthaving a cylindrically shaped bore, a main valve member slidably mountedin said bore of said valve chest to control the suppb and exhaust of theexpansive fluid to actuate the piston in the cylinder, said main valvemember having a pair of cylindrically shaped recesses, one in each outerend thereof, said recesses forming 'the actuating motor cylinderstherefor, each of of 'said valve chest, 0. cylindro-conical shoulderintermediate the two sizes of each projection, each of said shouldersbeing adapted to contact with and form a seal with its mate seatshoulder in its mate recess in said main valve chamber, and an annularshaped chamber adjoining the larger end of each of said disc shoulderswherein expansive fluid can be compressed to form dashpot cushioningmeans for said main valve chamber.

4. In a motor for a pump having a cylinder containing a reciprocablepiston member actuated within the cylinder by expansive fluid, a valvechest extending parallel to and secured to the cylinder, said chesthaving a cylindrically shaped bore, a main valve member slidably mountedin said bore of said valve chest to control the supply and exhaust ofthe expansive fluid to actuate the piston in the cylinder, said mainvalve member having a pair of cylindrically shaped recesses, one in eachouter end thereof, said recesses forming the actuating motor cylinderstherefor, each of said recesses having two diametrical sizes, afrusto-conical shoulder seat interposed between the two diametricalsizes, a pair of covers, one for each end of said valve chest bore, aninwardly extending projection on each cover having a slidable flt to thetwo sizes of its mate recess in the end of said main valve member, saidprojections providing the sole supporting means for said main valvemember centrally within the bore of said valve chest, a cylindro-conicalshoulder intermediate the two sizes of each projection, each of saidshoulders being adapted to contact with and form a seal with its mateseat shoulder in its.

mate recess in said main valve chamber, an annular shaped chamberadjoining the larger end of each of said disc shoulders whereinexpansive fluid can be compressed to form dash-pot cushioning means forsaid main valve chamber, and port communication means extending throughsaid inwardly extending projections through which to supply and exhaustthe expansive fluid actuating medium to and from said recesses.

5. In a motor for a pump having a cylinder containing a reciprocablepiston member actuated within the cylinder by expansive fluid, a valvechest extending parallel to and secured to the cylinder, said chesthaving a cylindrically shaped bore, a main valve member slidably mountedin said bore of said valve chest to control the supply and exhaust ofthe expansive fluid to actuate the piston in the cylinder, said mainvalve member having a pair of cylindrically shaped recesses, one in eachouter end thereof, said recesses forming the actuating motor cylinderstherefor, each of said recesses having two diametrical sizes, afrusto-conical shoulder seat interposed between the two diametricalsizes, a pair of covers, one for each end of said valve chest bore, aninwardly extending projection on each cover having a slidable fit to thetwo sizes of its mate recess in the en of said main valve chamber, saidprojections providing the sole supporting means for said main valvemember centrally within the bore of said valve chest, a cylindroconicalshoulder intermediate the two sizes of each projection, each of saidshoulders being adapted to contact with and form a seal with its mateseat shoulder in its mate recess in said main valve chamber, an annularshaped chamber adjoining the larger end of each of said disc shoulderswherein expansive fluid can be compressed to form dash-pot cushioningmeans for said main valve chamber, port communication means extendingthrough said inwardly extending projections through which to supply andexhaust the expansive fluid actuating medium to and from said recesses,and means in the form of a pair of cylindrically shaped pilot valves,one located adjoining each end of said cylinder, and operable by beingcontacted by said piston to control the expansive fluid supply to andexhaust from said recesses in said main valve member.

6. In a motor for a pump having a cylinder containing a reciprocablepiston member actuated within the cylinder by expansive fluid, a valvechest extending parallel to and secured to the cylinder, said chesthaving a cylindrically shaped bore, a main valve member slidably mountedin said bore of said valve chest to control the supply and exhaust ofthe expansive fluid to actuatethe piston in the cylinder, said mainvalve member having a pair of cylindrically shaped recessess, one ineach outer end thereof, said recesses forming the actuating motorcylinders therefor, each of said recesses having two diametrical sizes,a frusto-conical shoulder seat interposed between the two diametricalsizes, a pair of covers, one for each end of said valve chest bore, aninwardly extending projection on each cover having a slidable fit to thetwo sizes of its mate recess in the end of said main valve member, saidprojections providing the sole supporting means for said main valvemember centrally within the bore of said valve chest, a cylindro-conicalshoulder intermediate the two sizes of each projection, each of saidshoulders being adapted to contact with and form a seal with its mateseat shoulder in its mate recess in said main valve chamber, an annularshaped chamber adjoining the larger end of each ofsaid disc shoulderswherein expansivefluid can be compressed to form dash-pot cushioningmeans for said main valve chamber, port communication means extendingthrough said inwardly extending projections through which to supply andexhaust the expansive fluid actuating medium to and from said recesses,means in the form of a pair of cylindrically shaped pilot valves, onelocated adjoining each end of said cylinder and operable by beingcontacted by said piston to control the expansive fluid supply to andexhaust from said recesses in said main valve member, and means externalto said valve chest for manually restricting the exhaust fluid outletfrom said recesses in said main valve member and for the purpose ofmanually controlling both the length of stroke of said piston and thecushioning of said main valve member.

'7. In a motor for a pump having a cylinder containing a reciprocablepiston member actuated within the cylinder by expansive fluid, a valvechest extending parallel to and secured to the cylinder, said chesthaving a cylindrically shaped bore, a main valve member slidably mountedin said bore of said valve chest to control the supply and exhaust ofthe expansive fluid to actuate the piston in the cylinder, said mainvalve member having a pair of cylindrically shaped recesses, one in eachouter end thereof, said recesses forming the actuating motor cylinderstherefor, each of said recesses having two diametrical sizes, afrusto-conical shoulder seat interposed between the two diametricalsizes, a pair of covers, one for each end of said valve chest bore,

an inwardly extending projection on each cover having a slidable flt tothe two sizes of its mate recess in the end of said main valve member,said projections providing the sole supporting means for said main valvemember centrally within the bore of said valve chest, a cylindro-conicalshoulder intermediate the two sizes of each projection, each of saidshoulders being adapted to contact with and form a seal with its mateseat shoulder in its mate recess in said main valve chamber, portcommunication means extending through said inwardly extendingprojections through which to supply and exhaust the expansive fluidactuating medium to and from said recesses, means in the form of a. pairof cylindrically shaped pilot valves, and one located adjoining each endof said cylinder, operable by being contacted by said piston to controlthe expansive fluid supply to and exhaust from said recesses in saidmain valve member.

8. In a motor for a pump having a cylinder containing a reciprocablepiston member actuated within the cylinderby expansive fluid, a valvechest extending parallel to and secured to the cylinder, said chesthaving a cylindrically shaped bore, a main valve member slidably mountedin said bore of said valve chest to control the supply and exhaust ofthe expansive fluid to actuate the piston'in the cylinder, said mainvalve member having a pair of cylindrically shaped recesses, one in eachouter end thereof, said recesses forming the actuating motor cylinderstherefor, each of said recesses having two diametrical sizes, a

frusto-conical shoulder seat interposed between the two diametricalsizes, a pair of covers, one for each end of said valve chest bore, aninwardly extending projection on each cover having a slidable fit to thetwo sizes of its mate recess in the end of said main valve member, saidprojections providing the sole supporting means for said main valvemember centrally within the bore of said valve chest, a cylindroconicalshoulder intermediate the two sizes of each projection, each of saidshoulders being adapted to contact with and form a seal with its mateseat shoulder in its mate recess in said main valve chamber, portcommunication means extending through said inwardly extendingprojections through which to supply and exhaust the expansive fluidactuating medium to and from said,recesses, means in the form of a pairof cylindrically shaped pilot valves, one located adjoining each end ofsaid cylinder and operable by being contacted by said piston to controlthe expansive fluid supply to and exhaust from'said recesses in saidmain valve member, and means external to said valve chest for manuallyrestricting the exhaust fluid outlet from said recesses in said mainvalve member and for the purpose of manually controlling both the lengthof stroke of said piston and the cushioning of said main valve member.

FRANK DAVID BUTLER.

